FR2925484A1 - Use of at least one 3,4,5-trihydroxy-benzoic acid methyl ester compounds as an additive for hydraulic binder, mortar or concrete, where the hydraulic binder is useful e.g. for the fabrication of elements or materials in construction - Google Patents

Abstract

Use of at least one 3,4,5-trihydroxy-benzoic acid methyl ester compounds (I) or their salts as an additive for hydraulic binder, mortar or concrete, is claimed. Use of at least one 3,4,5-trihydroxy-benzoic acid methyl ester compounds of formula (I) or their salts as an additive for hydraulic binder, mortar or concrete, is claimed. R 1>, R 2>1-4C alkyl; R 3>H, 1-18C alkyl, OH or 1-18C alkoxy; and n : 0-100. Independent claims are included for: (1) the hydraulic binder comprising (I); and (2) concrete or mortar, comprising (I). [Image].

Description

Use of derivatives of gallic acid as additives for hydraulic binders, mortars or concretes

The present invention relates to the use of derivatives of gallic acid as additives for hydraulic binders, mortars or concretes.

It is known to use adjuvants during the implementation of hydraulic binders, mortars or concretes, in order to provide them with particular properties. Examples include fluidifiers, which control the rheology of hydraulic binders, mortars or concretes before curing, accelerators or retarders of setting hydraulic binders, mortars or concretes that control the setting time, water reducing agents which allow to add less water for the hydration of hydraulic binders, mortars or concretes, air entrainment agents which make it possible to create networks of bubbles and lighten the material, etc.). In particular, it is useful to control the rheology of hydraulic binders, mortars or concretes in order to facilitate their handling and / or placement. Thus, the user can benefit from a period of time, called period of workability, during which the hydraulic binder, mortar or hydrated concrete remains fluid and manipulable. Having a mastery of the workability period allows in particular to be able to work the hydraulic binder, mortar or fresh concrete for a given time, for example before pouring it into a formwork to obtain the desired element after curing. Adjuvants used for this purpose are commonly referred to as fluidifiers. The terms plasticizers and water reducers can also be used.

In the field of fluidizers for hydraulic binders, mortars or concretes, there are two categories: the medium water reducing agents (or Middle Water Reducing Agents, abbreviated as MWRA) and the highly water reducing agents (High Water Reducing). Agents in English, abbreviated as HWRA). Among the MWRAs, there may be mentioned lignosulphonates, sugars and their derivatives, or gluconate.

HWRAs are also called superplasticizers, and provide a greater fluidifying effect than MWRAs. Included in this category are polyalkoxylated polycarboxylic acids, polynaphthalenesulfonates, or polymelaminesulfonates. In the field of MWRA, it is known to use gluconate, especially sodium or calcium, for its fluidifying properties. On this subject, one can for example refer to the publication of PEREZ JP. entitled "The Mechanism of Action of Sodium Gluconate on the Fluidity and Set of Portland Cernent." Proceeding of the 12th International congress on the chemistry. Montreal. 2007. 1 However, when using gluconate, it is known that the more the amount of gluconate in the hydraulic binder, mortar or concrete, the more the fluidizing effect increases, but also the retardation of setting increases. In addition, there is a concentration, which varies depending on the nature of the various constituents of the hydraulic binder, mortar or concrete, beyond which the fluidizing effect no longer increases. At this stage, an increase in the gluconate concentration causes a very significant increase in the setting delay. At this time, the setting delay is increased in such a way that the setting of the hydraulic binder, mortar or concrete can not take place within a reasonable time.

The term "plug" according to the present invention means the passage of the hydraulic binder, mortar or hydrated concrete in the cured state. In this regard, one can for example refer to the publication of Nonat A. and Mutin J. entitled: "From hydration to setting". Proceeding of the international RILEM workshop. Edited by E & FN SPON. pp171-192. 1991.

Fresh or fresh state according to the present invention means the first instants of hydration, where the hydraulic binder paste, mortar or hydrated concrete is malleable. The term hardened or hardened state according to the present invention the moment of hydration, where the hydraulic binder, mortar or concrete has mechanical strength.

The problem to be solved by the invention is to provide a new means adapted to fluidize hydraulic binders, mortars or concretes, with a controlled effect on the retardation of setting.

Unexpectedly, the inventors have demonstrated that it is possible to use, for fluidifying hydraulic binders, mortars or concretes with a controlled effect on the retardation of setting, certain derivatives of gallic acid.

For this purpose, the present invention proposes the use of at least one compound of general formula (I) or one of its OH salts R 1 I R 3 (OR 2) n (I) 2 in which: R 1 represents a linear or branched alkyl radical in C1 to C4; R2 represents a linear or branched C1-C4 alkyl radical; R3 represents a hydrogen atom, a linear or branched C1 to C18 alkyl radical, an OH radical or a C1 to C18 alkoxy radical; n is an integer from 0 to 100; as an adjuvant for hydraulic binder, mortar or concrete.

On the other hand, the invention relates to a hydraulic binder comprising at least one compound of general formula (I) or a salt thereof.

Furthermore, the invention relates to a concrete or mortar, which comprises at least one compound of general formula (I) or a salt thereof. In addition, the invention relates to a concrete or mortar, which comprises at least one hydraulic binder as defined above.

The invention furthermore relates to the use of a hydraulic binder, a mortar or a concrete as defined above, in the fields of prefabrication, ready-to-use concretes or the manufacture of mortars.

Similarly, the invention relates to the use of a hydraulic binder, a mortar or a concrete as defined above, for the manufacture of elements or materials for the field of construction.

Finally, the invention relates to elements or materials for the field of construction obtained from a hydraulic binder, a mortar or a concrete comprising at least one compound of general formula (I) or one of its salts.

The invention offers decisive advantages, in particular certain gallic acid derivatives according to the invention are more efficient at high concentrations than certain MWRAs, for example gluconate. In particular, the fluidizing effect of the compounds according to the invention continues to increase with the concentration of the fluidizer according to the invention, where the effect with the gluconate stops.

In addition, the invention has the advantage of being able to be implemented in all industries, in particular the cement industry, the chemical industry (adjuvants), the mortar-making industry, the concrete plants, and in the areas of building, construction, admixtures, pre-fabrication.

Other advantages and features of the invention will become clear from reading the description and examples, given purely by way of non-limiting illustration, which will follow.

The invention relates to the use of at least one compound of general formula (I) or one of its salts OH (I) R2 R3 n in which: R1 represents a linear or branched C1-C4 alkyl radical; R2 represents a linear or branched C1-C4 alkyl radical; R3 represents a hydrogen atom, a linear or branched C1 to C18 alkyl radical, an OH radical or a C1 to C18 alkoxy radical; n is an integer from 0 to 100; As an adjuvant for hydraulic binder, mortar or concrete.

The expression "adjuvant" means any product which makes it possible to provide particular properties for a hydraulic binder, a mortar or a concrete (see standard NF 934-2). The terms additives or agents may also be used. The term "binder" means any compound which, when mixed with water, forms a paste which hardens with the acquisition of mechanical properties. By the term hydraulic binder is meant any binder having the property of hydrating and hardening under water. Mention may in particular be made of cements (Portland cement, aluminous cements, etc.) or also cementitious (limestone, pozzolana, fly ash, slag, metakaolin, silica fume, etc.), alone or in combination. By the terms concrete or mortar means any compositions comprising a hydraulic binder, water and aggregates, the aggregates may have varying sizes. These compositions may further include sands, fillers, adjuvants, such as fluidifiers, accelerators / setters, superplasticizers, air entraining agents, viscosifying agents, etc., alone or in combination.

According to a preferred embodiment of the invention, the compound (I) or one of its salts is used as a plasticizer. The Applicant has in fact surprisingly discovered that the compound (I) or one of its salts makes it possible to fluidify the hydraulic binders, mortars or concretes in the fresh state, while having control over the retardation of setting. This advantage significantly differentiates the adjuvant according to the invention from conventional fluidizers of the MWRA type, and more particularly gluconate.

Advantageously, the radical R 1 of the compound (I) is a linear or branched C1 or C2, preferably C2, alkyl radical. Preferably, the radical R2 of the compound (I) is a linear or branched C2 or C3 alkyl radical. Preferably, the radical R 3 of the compound (I) is a linear or branched C1 to C4 alkyl radical, advantageously a C1-alkoxy radical. Advantageously, the number n of the compound (I) is between 0 and 50, in particular between 0 and 20. Preferably, the number n of the compound (I) is between 10 and 25, preferably between 15 and 20. In particular, when the number n is equal to 0, the radical R 3 is preferably an alkyl radical. linear or branched C1 to C4. The compound according to formula (II) is preferably used as an adjuvant for hydraulic binder, mortar or concrete.

According to a preferred embodiment of the invention, the hydraulic binder is chosen from all cements. The compound (I) according to the invention can be added at various stages of production and use of hydraulic binders, and in particular during the manufacture of hydraulic binders, before, during or after the grinding stage, during the manufacture of mortars or concretes, before or during mixing, mixed with or separately with mixing water, etc. The compound (I) may for example be used in the form of a solution, an emulsion or a powder, by simple mixing, spraying, adding, dissolving, or any other method known to those skilled in the art. The addition of the compound (I) to the hydraulic binder, mortar or concrete can in particular be carried out in a cement plant, in a concrete batching plant, during or after the loading of the truck-top, or on site.

Preferably, the adjuvant according to the invention may be used in the form of a solution and may be added to the hydraulic binder, mortar or concrete in a concrete batching plant, at the same time as the mixing water, or delayed.

Advantageously, the concentration of the compound (I) is between 0.05 and 1.0%, preferably between 0.05 and 0.5%, advantageously between 0.075 and 0.2%, the percentages being expressed by dry weight per relative to the dry weight of hydraulic binder.

The adjuvant according to the invention can be used alone or in combination with other plasticizers and / or other adjuvants, for example accelerators / retarders, superplasticizers, air entraining agents, viscosifying agents. etc. Moreover, the adjuvant according to the invention may preferably be composed of a mixture of several compounds (I). For example, the adjuvant may comprise a mixture of compounds (I) with a number n between 15 and 20.

The invention further relates to the use as described above, knowing that the compound of general formula (I) can be obtained by an esterification carried out without significant addition of solvent, in other words by mass. In fact, in a conventional manner, the esterifications are carried out in the presence of a solvent, the various reagents being added to each other in the form of solutions. However, although this alternative also works to obtain the plasticizer according to the invention, the Applicant has surprisingly found that the esterification was much better when the reactants are mixed without significant addition of solvent. In this way, a homogeneous and stable mixture is obtained which makes it possible to easily obtain the compound according to the general formula (I).

In particular, at least one of the reagents is added in dry form, for example in the form of powder or wax. Preferably, all the reagents are added in the form of powder and / or wax. For example, it is possible to mix gallic acid or one of its derivatives in the form of a powder, a polyalkylene glycol alkyl in the form of a wax and a catalyst in the form of a powder. The compounds of general formula (I) can be obtained by esterification reaction of gallic acid or one of its derivatives with methoxypolyethylene glycols according to the following reaction: OH + OH-R1- (O-R2) ä -R pop, -R1- (O-R2)) - R3 OH HO Cat. 4 HO 'OH + ROH in which:

R represents a hydrogen atom or a linear or branched alkyl radical R1, R2 and R3 have the meaning mentioned above. Preferably, R is a C1 to C20 linear alkyl radical. In order to improve the reaction yields, the use of a catalyst (Cat.) Is

15 possible. The catalyst preferably used is para-toluenesulphonic acid (APTS) but hydrochloric acid (HCl) or lithium hydroxide (LiOH) can also be chosen. It is furthermore preferable that the by-product ROH formed during the synthesis is continuously removed from the reaction medium by distillation. 20

On the other hand, the invention relates to a hydraulic binder comprising at least one compound of general formula (I) or a salt thereof. Wherein R1 represents a linear or branched C1-C4 alkyl radical; R2 represents a linear or branched C1-C4 alkyl radical; R3 represents a hydrogen atom, a linear or branched C1 to C18 alkyl radical, an OH radical or a C1 to C18 alkoxy radical; OH 7 n is an integer from 0 to 100.

Advantageously, the radical R 1 of the compound (I) is a linear or branched C1 or C2, preferably C2, alkyl radical.

Preferably, the radical R2 of the compound (I) is a linear or branched C2 or C3 alkyl radical. Preferably, the radical R 3 of the compound (I) is a linear or branched C1 to C4 alkyl radical, advantageously a C1-alkoxy radical. Advantageously, the number n of the compound (I) is between 0 and 50, in particular between 0 and 20. Preferably, the number n of the compound (I) is between 10 and 25, preferably between 15 and 20. According to a preferred embodiment of the invention, the hydraulic binder is selected from all cements. Advantageously, the concentration of the compound (I) in the hydraulic binder is between 0.05 and 1.0%, preferably between 0.05 and 0.5%, advantageously between 0.075 and 0.2%, the percentages being expressed in dry weight relative to the dry weight of hydraulic binder.

The invention also relates to a mortar or concrete comprising at least one compound of general formula (I) or an OH salt thereof (I) in which: R1 represents a linear or branched C1-C4 alkyl radical; R2 represents a linear or branched C1-C4 alkyl radical; R3 represents a hydrogen atom, a linear or branched C1 to C18 alkyl radical, an OH radical or a C1 to C18 alkoxy radical; n is an integer from 0 to 100.

Advantageously, the radical R 1 of the compound (I) is a linear or branched C1 or C2, preferably C2, alkyl radical. Preferably, the radical R2 of the compound (I) is a linear or branched C2 or C3 alkyl radical.

Preferably, the radical R 3 of the compound (I) is a linear or branched C 1 to C 4 alkyl radical, advantageously a C 1 -C 4 alkoxy radical.

Advantageously, the number n of the compound (I) is between 0 and 50, in particular between 0 and 20. Preferably, the number n of the compound (I) is between 10 and 25, preferably between 15 and 20.

According to a preferred embodiment of the invention, the hydraulic binder is selected from all cements.

Advantageously, the concentration of the compound (I) in the mortar or concrete is between 0.05 and 1.0%, preferably between 0.05 and 0.5%, advantageously between 0.075 and 0.2%, the percentages being expressed in dry weight relative to the dry weight of hydraulic binder.

The invention also relates to a mortar or a concrete comprising the hydraulic binder as defined above. The invention furthermore relates to the use of a hydraulic binder, a mortar or a concrete as described previously in the areas of prefabrication, ready-mix concrete or mortar-making. In addition, the invention relates to the use of a hydraulic binder, a mortar or a concrete as described above for the manufacture of elements or materials in the field of construction. For example, the hydraulic binder, mortar or concrete according to the invention may be cast in a mold making it possible to form parts for the field of prefabrication. The invention further relates to elements or materials for the field of construction obtained from a hydraulic binder, a mortar or a concrete comprising at least one compound of general formula (I) or a salt thereof In which: R1 represents a linear or branched C1-C4 alkyl radical, R2 represents a linear or branched C1-C4 alkyl radical, R3 represents a hydrogen atom, a hydrogen atom, a linear or branched C1-C4 alkyl radical; linear or branched C1 to C18 alkyl radical, an OH radical or a C1 to C18 alkoxy radical; n is an integer from 0 to 100.

Advantageously, the radical R 1 of the compound (I) is a linear or branched C1 or C2, preferably C2, alkyl radical.

Preferably, the radical R2 of the compound (1) is a linear or branched C2 or C3 alkyl radical. Preferably, the radical R 3 of the compound (I) is a linear or branched C1 to C4 alkyl radical, advantageously a C1-alkoxy radical. Advantageously, the number n of the compound (I) is between 0 and 50, in particular between 0 and 20. Preferably, the number n of the compound (I) is between 10 and 25, preferably between 15 and 20. According to a preferred embodiment of the invention, the hydraulic binder is selected from all cements. Advantageously, the concentration of the compound (I) is between 0.05 and 1.0%, preferably between 0.05 and 0.5%, advantageously between 0.075 and 0.2%, the percentages being expressed by dry weight per relative to the dry weight of hydraulic binder.

FIG. 1 represents the spreading of mortars as a function of the adjuvant dosage for mortars comprising different adjuvants. Figure 2 shows the variation in setting delay between an adjuvanted mortar compared to a nonadjuvanted mortar as a function of the adjuvant dosage for mortars comprising different adjuvants.

The mortar or concrete according to the invention can be manufactured in a conventional manner. The following examples illustrate the invention without limiting its scope. EXAMPLES In the following examples, compound 1 corresponds to methyl gallate, compound 2 to formula (II), compound 3 to ethyl gallate and compound 4 to propyl gallate. Preparation of the Adjuvant According to the Invention Example of Procedure for Compound 2 A mixture of 52.64 g of powdered gallic acid (equivalent to 0.3 moles), 247.50 g (equivalent to 0.33 moles) of Polyethylene Glycol 750 Methacrylate (MPEG 750) in the form of a wax and 7.538 g of para-toluenesulphonic acid (APTS) in powder form is refluxed for 32 hours. All of the reagents are in a glass flask which is stirred continuously using an electromagnetic stirrer and heated by an oil bath at the set temperature of 125 ° C. The water resulting from the reaction is removed continuously by evaporation under vacuum. This water is recovered at the end of the cooling column in a distillate recovery flask. After 32 hours of reaction, the mixture is allowed to cool to room temperature (about 20-22 ° C) and diluted in demineralized water to obtain a final solution with an active content of about 50%. The yield of the synthesis is 70%. This yield is deduced from the amount of residual MPEG 750 found by HPLC analysis.

Preparation and composition of the mortar on which the tests are carried out o Mortar formula: Different mortar formulations were made. These include a different concentration of adjuvant (from 0 to 0.4%). The typical mortar formulation is given in the following table: EMC cement 152.5 N 809 g Sand standardized 2700 g (CEN EN 196-1 standard) Total water 507 g including 162 g prewetting Adjuvant 0/0 on a dry weight basis to the dry weight of cement o Procedure: Introduce the sand into the bowl of the Perrier kneader. From 0 to 60 seconds, start mixing at speed 1, and introduce the pre-wetting water in 30 seconds. 11 Let stand 3 minutes. Introduce the cement. Mix for 1 minute at speed 1. (TO) Add the mix water containing the adjuvant in 30 seconds.

Mix for 1 minute at speed 2. Comparative example in terms of spreading and setting time of several adjuvants according to the invention and gluconate o Measurement of spreading at t = 5min

The spreading of the mortars is evaluated by means of a mini cone of Abrams (height: 15 cm, diameter less than 10 cm and diameter greater than 5 cm). The cone is positioned on the work surface, so that the volume defined by the interior of the cone and the work plan forms a cavity. This cavity is completely filled with mortar to test, in two layers by stitching 20 times between each. Then the cone is lifted gently. Then the mortar to be tested spreads out on the worktop. The diameter of the disk formed by the mortar is measured. o Measurement of setting time

The measurement of the setting time is carried out on the following formulation: EMC Cement 152.5 N 7g Water 80mL Adjuvant% by dry weight relative to the dry weight of cement

As for plating, several mortars were tested, containing a different concentration of adjuvant (from 0 to 0.4%). The setting time is then measured by conductimetry. The setting delay, shown in Figure 2, is calculated as follows: setting time of a non-additive mortar minus the setting time of mortars with different amounts of adjuvant.

In Figures 1 and 2, the percentage of adjuvant is expressed by dry weight relative to the dry weight of cement. According to FIG. 1, in the case of gluconate and compound 1, the curves are identical and are characterized by different points and singular segments: • A plateau (from 0 to about 0.025%): where, addition of gluconate in small quantities does not allow to fluidize the system up to a threshold value. • Then, from 0.025 to 0.1%, the more the amount of gluconate increases, the more the fluidity increases. This phenomenon is proportional to a saturation value (about 0.1%). Finally, beyond about 0.1%, the addition of gluconate no longer makes it possible to modify the rheology of the system. In the case of compound 2, the fluidity of the mortar increases linearly with the adjuvant dosage. It makes it possible to obtain a greater fluidity than that obtained with gluconate at similar concentrations.

From Figure 2, in the case of gluconate, two successive linear domains are observed: - a low retarding domain for low concentrations of adjuvant - a highly retarding domain for higher concentrations of adjuvant.

In the concentration range studied, compound 1 exhibits a retardation effect which is directly related to the adjuvant content. Indeed, the setting time increases linearly with the addition of compound 1 from 0 to 0.3% of adjuvant. This linearity is advantageous according to the invention compared with gluconate, which has two domains of behavior. Compound 2 for concentrations of 0 to 0.4% dry weight has a slight retardation effect compared to the non-adjuvanted control. 20 13

Claims (13)

Use of at least one compound of general formula (I) or an OH (I) salt thereof in which: R1 represents a linear or branched C1-C4 alkyl radical; R2 represents a linear or branched C1-C4 alkyl radical; R3 represents a hydrogen atom, a linear or branched C1 to C18 alkyl radical, an OH radical or a C1 to C18 alkoxy radical; n is an integer from 0 to 100; as an adjuvant for hydraulic binder, mortar or concrete. 2- Use according to claim 1, characterized in that the compound (I) or one of its salts is used as a plasticizer. 3- Use according to one of claims 1 or 2, characterized in that the radical R1 of the compound (I) is a linear or branched C1 or C2 alkyl radical, preferably C2. 25 4- Use according to any one of the preceding claims, characterized in that the radical R2 of the compound (I) is a linear or branched C2 or C3 alkyl radical. 5- Use according to any one of the preceding claims, characterized in that the radical R3 of the compound (I) is a linear or branched C1 to C4 alkyl radical, advantageously a C1-alkoxy radical. 35 6. Use according to any one of the preceding claims, characterized in that the number n of the compound (I) is between 10 and 25, preferably between 15 and 20. 7- Use according to any one of the preceding claims, characterized in that the hydraulic binder is selected from all cements. 45 8- Use according to any one of the preceding claims, characterized in that the concentration of the compound (I) is between 0.05 and 1.0%, preferably between 0.05 and 0.5%, preferably between 0.075 and and 0.2%, the percentages being expressed by dry weight relative to the dry weight of hydraulic binder. 9- Use according to any one of claims 1 to 8, characterized in that the compound of general formula (I) is obtained by an esterification carried out without significant addition of solvent, in other words by mass. 10- Use according to claim 9, characterized in that at least one of the reagents is added in dry form. 11- Hydraulic binder comprising at least one compound of general formula (I) or an OH salt thereof (I) in which: R1 represents a linear or branched C1-C4 alkyl radical; R2 represents a linear or branched C1-C4 alkyl radical; R3 represents a hydrogen atom, a linear or branched C1 to C18 alkyl radical, an OH radical or a C1 to C18 alkoxy radical; n is an integer from 0 to 100. 20 12- Concrete or mortar, characterized in that it comprises at least one compound of general formula (I) or one of its salts R1 ((oR2) R3 n OH (I) in which: R1 represents a linear alkyl radical or branched C1 to C4; R2 represents a linear or branched C1 to C4 alkyl radical; R3 represents a hydrogen atom, a linear or branched C1 to C18 alkyl radical, an OH radical or a C1 to C18 alkoxy radical; N is an integer from 0 to 100. 13- Concrete or mortar, characterized in that it comprises at least one hydraulic binder according to claim 11. OH15- Use of a hydraulic binder according to claim 11, or a mortar or concrete according to any one of the claims 12 or 13, in the fields of prefabrication, ready-mix concrete or mortar-making. 15- Use of a hydraulic binder according to claim 11, or a mortar or concrete according to any one of claims 12 or 13, for the manufacture of elements or materials for the field of construction. 16- Elements or materials for the field of construction obtained from a hydraulic binder, a mortar or a concrete comprising at least one compound of general formula (I) or one of its salts O R2 R3 n OH (I) wherein: R1 represents a linear or branched C1-C4 alkyl radical; R2 represents a linear or branched C1-C4 alkyl radical; R3 represents a hydrogen atom, a linear or branched C1 to C18 alkyl radical, an OH radical or a C1 to C18 alkoxy radical; n is an integer from 0 to 100. 16